Method for stabilization processing of color emulsions



United States Patent N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey N0 Drawing. Filed Dec. 9, 1963, Ser. No. 329,290 7 Claims. (Cl. 96-22) This invention relates to processing color photographic emulsions, and more particularly to rapid processing of coupler incorporated silver halide photographic emulsions.

In the preparation of silver halide emulsions for recording colors, it is customary to incorporate a colorforming material in the silver halide emulsion so that upon development this color-forming compound (coupler) reacts with the oxidation product of the developing agent to form a dye. 'In the typical emulsion for recording the Visible spectrum, the emulsion is coated in several layers, each sensitive to a particular region of the spectrum. By suitable control of the development and by use of several couplers, it is possible to form the proper dye in each layer to give an adequate color representation of the light image producing the original exposure.

The use of color emulsions is particularly advantageous in recording the high speed fluctuations of electric current in recording instruments of various types, including oscillographs, since the color response permits the recording of several beams of light of different colors.

It has been customary for recording instruments to employ galvanometers provided with mirrors, which are responsive to fluctuation in an electric circuit. Direct beams of light reflected from the mirrors onto a moving web contained in a camera record the fluctuation. A typical system is described in Heiland US. Patent 2,580,427, issued J an. 1, 1952. Also, instruments are available which produce variable area light beams or light beams of variable intensity. Examples of such intruments are the Triple Recording Oscillograph, TRO-G, manufactured by -SIE, Division of Dresser Electronics, Houston, Tex., which produces multiple displays of the conventional trace, variable density and variable area; and the PB50 Field Ofiice Seismic Data Reduction System, manufactured by the Electrodynamic Instrument Corporation, Houston, Tex., which produces a conventional trace or variable density cross sections.

Black-and-white recording papers have been preferred for many purposes due to the speed of processing. For instance, print-out emulsions are susceptible to producing a visible image shortly after being exposed. However, while the black-and-white papers have been very fast, they have had limited information storage capacity per unit area because superimposed signals become incoherent.

It has been desirable to use color emulsions with considerably increased information storage capacities, but with rapid processing compared to the conventional processing systems which require several processing steps including washing to remove residual processing chemicals.

It has been particularly desirable to improve the processing rate and stabilization of color emulsions which are designed for use in recording oscillograph traces.

We have found a method of stabilization processing of coupler containing color emulsions which has an improved developing rate and does not require a washing operation.

One object of this invention is to provide a system for stabilization processing of coupler containing silver halide color emulsions. Another object is to provide processing solutions which can be used for the processing of silver halide color emulsions. A further object is to provide a processing system for use with color papers designed for recording oscillograph traces. A further object it to provide a color developer which forms dyes from the coupler in the silver halide emulsion. An additional object is to provide a bleach-stabilizer bath which is more stable than previous bleach-fixing baths and possesses sufficient potential to convert the leuco dye to the colored form. A still further object is to provide a stabilizer for coupler containing silver halide color emulsions which decolorizes the salts carried over from previous processing solutions, permits good drying, particularly at high temperatures, and stabilizes the print against chemical action of residual chemicals.

The above objects are attained by using a 4-step process comprising a developer, stop bath, bleach-stabilizer, and stabilizer.

DEVELOPER The developing agent is an alkaline solution containing a primary aromatic amine of the p-phenylenediamine type in which the two hydrogens of one amino group are replaced by alkyl groups. Typical couplers which react with the developing agent are described in Marines and Godowsky US. Patent 2,304,940, granted Dec. 15, 1952, Jelley and Vittum US. Patent 2,322,027, granted June -15, 1943, Peterson US. Patent 2,296,306, granted Sept. 22, 1942, and Fischer US. Patent 1,102,028, granted June 30, 1914.

For instance, the developing agent 4-amino-N-ethyl-N- 8 methanesulfonamidoethyl)-m-toluidine sesquisulfate monohydrate used in the developer solution of Example 1 can be replaced with other conventional p-phenylenediamine developing agents, such as, for example, 4-amino- N ethyl-N-B-hydroxyethyla-methylaniline sulfuric acid salt, N ethyl B methanesulfonamidoethyl 3 methyl- 4- aminoaniline sulfate, N-ethyl-B-methanesulfonamidoethyl-4-aminoaniline, 2-amino-S-diethylaminotoluene hydrochloric acid salt, 4-N-ethyl-N-fl-hydroxyethylaminoaniline, etc. All of these developing agents are characterized by having one primary amine group.

In our preferred embodiment, we use 4-amino-3-methyl- N-ethy1-N-(fl-hydroxyethyl)-aniline sulfate as the chromogenic developing agent. An inorganic alkaline sulfite such as, for example, an ammonium or an alkali metal sulfite such as sodium sulfite is added as a preservative and an inorganic alkaline bromide such as, for example, an ammonium or an alkali metal bromide, such as potassium bromide as a restrainer. Other materials may be added, such as formaldehyde, 2-nitro-2-(hydroxymethyD- 1,3-propanediol, etc. A particularly useful additive is from 0.1 to 0.3 gram per liter of dimezone (1-phenyl-4,4- dimethyl-3-pyrazolidone) STOP BATH BLEACH-STABILIZER This solution converts the developed silver to a silver salt, stabilizes this silver salt and converts any leuco dye to the more highly colored form. An inorganic alkaline ferricyanide such as, for example, an alkali metal or ammonium ferricyanide, preferably potassium ferricyanide, is used as an oxidizing agent; an inorganic alkaline thiocyanate such as, for example, an alkali metal or ammonium thiocyanate as a stabilizing agent, and an inorganic alkaline phosphate such as, for example, an alkali metal phosphate as a corrosion inhibitor and buffering agent. An inorganic alkaline bichromate such as, for example, an alkali metal or ammonium bichromate is also present in small amounts. This serves to extend the useful pH range of the bleach and avoids premature decomposition.

3 STABILIZER The stabilizer comprises an alkaline such as, for example, an alkali metal or ammonium bisulfite or sulfite with either an alkaline such as, for example, an alkali metal or ammonium phosphate or an alkaline such as, for example, an alkali metal or ammonium thiosulfate, and preferably has a pH of less than 7.0. Other components such as zinc sulfate, a zinc sequestering agent and the like may also be added.

The solutions are mixed With water. The following shows a typical 4-bath system with useful proportions of the components.

Ammonium thiocyanate 70-120 Potassium bichromate 2-10 Sodium phosphate, dibasic 5-60 Sequestrene Na, 2-10 Water to 1 liter. Stabilizer:

Sodium thiosulfate (crystal) 0-50 Sodium sulfite 50-150 Sodium bisulfite 50-200 Zinc sulfate 0-20 Diethylene triamine penta acetic acid 0-8 Water to 1 liter.

As an alternative stabilizer, the following may be used:

Grams/liter Sodium thiosulfate (crystal) 0-50 Sodium sulfite 25-250 Sodium phosphate 50-100 Sodium bisulfite 25-125 Water to 1 liter.

Various color emulsions may be used and these emulsions may comprise various layer arrangements. For instance, the support may carry thereon a blue-sensitive layer containing a yellow coupler, an interlayer, a greensensititve layer containing cyan and magenta couplers and having thereon an overcoat. These couplers may occur in different layers and in different orders as a matter of choice. It will be appreciated that various supports known in the art may be used for the silver halide emulsion and that if the transparent support is used, that one or more light-sensitive layers may be coated on one side and one or more layers on the other side. Another useful photographic element may have a bleachable filter layer incorporated in the element between two lightsensitive layers or on the support when it is between the light-sensitive layers. In still another useful element, the light-sensitive elements can have one or more strata of the type described in Millikan U.S. Ser. No. 159,057, filed Dec. 13, 1961. For example, one strata would be a high speed emulsion and the second strata a low speed emulsion both optically sensitized to the same portion of the spectrum and producing the same dye image. Similarly,

4 the second light-sensitive layer can have one or more strata.

The photographic emulsion may contain a single coupler or a combination of couplers in one or more of the light-sensitive layers.

In the silver halide emulsions in the color element, various silver salts may be used as the sensitive salts, including silver bromide, silver iodide, silver chloride or silver halide such as silver chlorobromide, silver bronioiodide, etc.

The emulsions can be chemically sensitized by any of the accepted procedures. The emulsions can be digested with naturally active gelatin, or sulfur compounds can be added such as those described in Sheppard U.S. Patent 1,574,944, issued Mar. 2, 1926; Sheppard et al. U.S. Patent 1,623,499, issued Apr. 5, 1927; and Sheppard et al. U.S. Patent 2,410,689, issued Nov. 5, 1946.

The emulsions can also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850, issued Nov. 15, 1949), polyamines, such as diethyl triamine (Lowe and Jones U.S. Patent 2,518,698, issued Aug. 15, 1950), polyamines, such as spermine (Lowe and Allen U.S. Patent 2,521,925, issued Sept. 12, 1950), or bis(B-aminoethyl)sulfide and its water-soluble salts (Lowe and Jones U.S. Patent 2,521,926, issued Sept. 12,1950).

In the preparation of the silver halide dispersions employed for preparing silver halide emulsions, there may be employed as the carrier for the silver halide in its preparation, gelatin or some other colloidal material such as colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound. Some colloids which may be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe U.S. Patent 2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester such as cellulose acetate hydrolyzed to an acetyl content of 19-26% as described in U.S. Patent 2,326,808 of Lowe and Clark, issued Aug. 24, 1943, a water-soluble ethanolamine cellulose acetate as described in Yutzy U.S. Patent 2,322,085, issued June 15, 1943; a polyacrylamine having a combined acryl-amide content of 30-60% and a specific viscosity of 0.25-1.5 on an imidized polyacrylamide of like acrylamide content and viscosity as described in Lowe, Minsk and Kenyon U.S. Pt'aent 2,541,474, issued Feb. 13, 1951; zein as described in Lowe U.S. Patent 2,563,791, issued Aug. 7, 1951; a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in Unruh and Smith U.S. Patent 2,768,154, issued Oct. 23, 1956; or containing cyano-acetyl groups such as the vinyl alcohol-vinyl cyanoacetate copolymer as described in Unruh, Smith and Priest U.S. Patent 2,808,331, issued Oct. 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a vinyl group as described in U.S. Patent 2,852,382, of Illingsworth, Dann and Gates, issued Sept. 16, 1958.

Included among the green sensitizers are acid merocyanines of Brooker et al. U.S. Patent 2,493,747, issued Jan. 10, 1950, such as 3-(p-carboxyphenyl)-5-(3-methyl- 2(3) benzoxazolylidene) rhodanine, 1 (p carboxyphenyl) 4 [3 ethyl 2(3) benzothiazolylidenisopropylidene] 3 methyl 5 pyrazolone, 3-ethyl-5-[3- ethyl) 2(3) benzoxazolyidene) ethylidene] 2 [3- methyl 5 oxo l-(p-sulfophenyl)-4-(2-pyrazolinylidene] 4 thiazolidone, etc., the merocyanines of Brooker et al. U.S. Patent 2,493,748, issued Ian. 10, 1950, such as 3 carboxymethyl 5 [3 methyl 2(3) thiazolinylidene)-ethylidene] 2 thio-2,4(3,5)-oxazoledione, 5 [3 ethyl 2(3) benzoxazolylidene) ethylidene]- 3 sulfomethyl 2-thio-2,4('3,5)-oxazoledione, etc.; the merocyanines of Sprague U.S. Patent 2,519,001, such as 5 [3 -,8 carboxyethyl 2(3) benzothiazolylidene)- ethylidene] 3 ethyl 1 phenyl 2 thiohydantoin, etc.; the cyanine dyes of Sprague U.S. Patent 2,503,776, issued Apr. 11, 1950, such as anhydro-5-chloro-1'-ethy1- 3-,B-sulfoethylthia-2-cyanine hydroxide, etc., and other sensitizers well known in the art.

Included among the blue sensitizers are acid merocyanines of Brooker et al. US. 2,493,747, issued I an. 10, 1950, such as 4-[(5-chloro-3-ethy1 2(3)-benzothiazolylidene) u ethylethylidene] 3 methyl 1 (psulfophenyl)-5-pyrozolone, etc.; the merocyanines of Brooker et al. US. Patent 2,493,748, such as 3-carboxymethyl 5-(3-ethyl-2(3 -benzothiazolylidene) rhodanine, etc., and other sensitizers well known in the art.

The following examples are intended to illustrate our invention but not to limit it in any Way.

Example 1 A gelatin sized strip of photographic paper support was coated with a layer comprising an ordinary gelatinosilver chlorobromide washed emulsion sensitized to blue light into which was intimately "blended two separate I dispersions in gelatin, one containing a dispersion (made as described in Ielley et al. US. Patent 2,322,027, issued June 15, 1943) of a solvent solution of a magenta-forming coupler and the other containing a solvent solution of a yellow forming coupled, such that approximately equal amounts of the couplers were present. This layer was coated with a gelatin interlayer containing a dispersion of dioctyl hydroquinone. The interlayer was coated with a layer comprising an ordinary gelatino-silver chlorobromide emulsion sensitized to green light and intimately blended with a dispersion (made as described in Jelley et al.) of a solvent solution of the cyan-forming coupler in gelatin. This layer was coated with a gelatin overcoat.

The photographic recording element of this example was exposed in a multichannel oscillograph in which three separate records were made with light beams reflected from three galvanometer actuated mirrors. One light beam was tungsten light passed through a Wratten No. 34 filter which transmits blue light, another light beam was tungsten light passed through a Wratten No. 12 filter which transmits green light, and a third beam was unfiltered tungsten light.

After exposure, the strip of our recording element was processed by immersing for 30 seconds at 100 F. in each of the following baths by passing the strip through the baths in succession.

Develop er Grams liter Sodium hydroxide 3.0 Sequestrene Na 2.0 (Ethylenediamine tetraacetic acid; tetra sodium salt) sodium phosphate, tribasic Sodium sulfite Potassium bromide 4 amino 3 methyl-N-ethyl-N-(fl-hydroxyethyl)-aniline sulfate 2 nitro-2-(hydroxymethyl)-1,3-pr-opanediol Water to make 1 liter.

Stop bath:

Sodium bisulfite Water to make 1 liter.

Bleach-stabilizer:

Potassium ferricyanide Ammonium thiocyan-ate Potassium bichromate Sodium phosphate, dibasic Water to make 1 liter.

Stabilizer:

Sodium thiosulfate (crystal) 50.0 Sodium sulfite 100.0 Sodium bisulfite 50.0 Zinc sulfate 20.0 Water to make 1 liter.

A good three channel record was obtained by processing the exposed element. The record made with the blue light beam was red, the record made with the green light beam was cyan, and the record made with the unfiltered light beam was a neutral density. Each record was clearly distinguishable from the other two.

Example 2 A similar exposed color paper as in Example 1 is tray processed in a cycle of one minute immersion in each bath with comparable results.

It will be appreciated that our processing solutions can be used to provide positive images with respect to the image formed in the light-sensitive material by the imbibition process. A typical process of this type is disclosed in Land, US. Patent 2,559,643. Conventional dye transfer papers may be used as the receiving paper such as the dye transfer paper sold by Eastman Kodak Company under the name Dye Transfer Double Weight F. Other image receiving layers may be used having a dye mordant thereon such as, for example, nickelous sulfate, aluminum sulfate, etc.

The term inorganic alkaline is used herein and in the claims to indicate alkali metal and ammonium compounds.

A particularly useful color product for use with the processing compositions of our invention is disclosed in pending Bodmer, Murphy, and Sterrett, United States application Ser. No. 205,642, filed June 27, 1962, now US. Patent 3,265,503.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. An improved rapid color photographic process which comprises developing with a primary aromatic amine color developing bath, an exposed color photographic material comprising differently sensitized gelatinosilver halide emulsions containing color formers capable of reaction with the oxidation product of said developer to form a dye, arresting development by passing through a stop bath containing an inorganic bisulfite, bleach sta bilizing with a bath containing an inorganic alkaline ferricyanide, an inorganic alkaline thiocyanate, an inorganic alkaline bicromate, and stabilizing with a bath containing an inorganic alkaline thiosulfate, an inorganic alkaline sulfite, and an inorganic alkaline bisulfite, said rapid process consisting of treating said photographic mate-rial in said developer, said stop bath, said bleachstabilizing bath and said stabilizing bath in the stated order with no washing, each of the said baths being designed to perform its indicated function in 30 seconds at F.

2. A color process of claim 1 in which the color de veloper is a primary aromatic amine of the p-phenylenediamine type in which the two hydrogens of one amino group are replaced by alkyl groups.

3. A process of claim 1 in which the color developer is selected from the class consisting of 4-amino-N-ethyl- N (B methanesulfonamidoethyl)-m-toluidene sesquisulfate monohydrate, 4-amino-N-ethyl-N-B-hydroxyethyl-3- methylaniline sulftrric acid salt, N-ethyl-fi-methanesulfonamidoethyl-3-methyl-4-aminoaniline sulfate, N-ethyl- [3 methanesulfonamidoethyl-4-aminoaniline, 2amino-5- diethylaminotoluene hydrochloric acid salt and 4-N-ethyl- N-B-hydroxyethylamino aniline.

4. An improved color photographic process which comprises developing an exposed color photographic material comprising differently sensitized gelatino-silver halide emulsions containing color formers capable of reaction With the oxidation product of a primary aromatic amine 7 to form a -dye comprising imbibing into the said material first a developer having the following composition:

Grams/liter Sodium hydroxide Ethylenediamine tetraacetic acid, tetra sodium salt, sodium phosphate, tribasic 30-100 Sodium sulfite 4-10 Potassium bromide 0.4-2.0

4 amino 3 methyl N ethyl N (fl-hydroxyethyl)-aniline sulfate 8-12 2-nitro-2-(hydroxymethyl)-1,3-p:ropanediol 1.0-4.0 Water to make 1 liter.

second, a stop bath having the following components:

Grams/liter Sodium bisulfite 20-60 Sodium sulfate 50-100 Water to make 1 liter.

and fourth, a stabilizer having the following components:

Grams/liter Sodium thiosulfate (crystal) 0-50 Sodium sulfite 50-150 Sodium bisulfite 50-200 Zinc sulfate 0-20 Diethylene triamine pent-a acetic acid 0-8 Water to make 1 liter.

said process using only the four solutions described hereinabove in the stated order using no washing step.

5. A composition for preparing a bleach-stabilizer bath for use in rapid bleach-stabilizing an image-exposed, rapidly color-developed photographic material which, after color development, has been immersed in a stop bath, but not washed, said composition comprising an inorganic alkaline ferricyanide, an inorganic alkaline thiocyanate, an inorganic alkaline phosphate and an inorganic alkaline bichromate, said bleach-stabilizer bath being capable of bleach-stabilization of said image-exposed photographic material in 30 seconds at 100 P. so that immediately following bleach-stabilization the said material can be stabilized in a stabilizer solution.

6. A bleach-stabilizer for use in treating an exposed color photographic material comprising differently sensitized gelatino-silver halide emulsions containing color formers capable of reaction with the oxidation product of a primary aromatic amine color developer to form dye images, said exposed material having been color developed, immersed in a stop bath, but not Washed, said bleach-stabilizer comprising:

Grams/liter Potassium ferricyanide 35-60 Ammonium thiocyanate -120 Potassium bichromate 2-10 Sodium phosphate, dibasic 5-60 Ethylenediamine tetraacetic acid, tetra sodium salt 2-10 Water to make 1 liter.

said solution being capable of bleach-stabilizing the said photographic material in 30 seconds at F. so that the bleach-stabilized material can be immediately stabilized in a stabilizing bath.

7. A process for bleach-stabilization of an exposed color photographic material that has been treated in a color developer, :and treated in a stop bath, said bleachstabilization step comprising imbibing into the said material a bleach-stabilizer having the following composition:

Grams/liter Potassium ferricyanide 35-60 Ammonium thiocyanate 70-120 Potassium bichromate 2-10 Sodium phosphate, dibasic 5-60 Ethylenediamine tetraacetic acid, tetra sodium salt 2-10 Water to make 1 liter.

said bleach stabilizer being capable of bleach-stabilizing the said material in 30 seconds at 100 F., said bleach stabilization step being followed directly by a stabilizing step, said color photographic material comprising differently sensitized gelatino-silver halide emulsions containing color formers capable of reaction with the oxidation products of a primary aromatic amine color developer to form dye images.

References Cited UNITED STATES PATENTS 2,691,588 10/1954 Henn et al. 96-66 2,760,404 8/1956 King 96-43 2,875,049 2/1959 Kridel 96-55 3,008,828 11/1961 Henn et al. 96-61 3,132,943 4/1964 Smith et al. 96-61 3,168,400 2/1965 Blackmer et al 96-22 3,189,452 6/1965 Bard et a1 96-61 3,265,503 8/1966 Bodmer et al. 96-74 FOREIGN PATENTS 695,689 8/ 1953 Great Britain.

774,545 5 1957 Great Britain.

856,907 12/1960 Great Britain.

879,443 10/ 1961 Great Britain.

OTHER REFERENCES Glafkides: Photographic Chemistry, pages 148-9, Fountain Press, London (1960).

NORMAN G. TORCHIN, Primary Examiner.

J. TRAVIS BROWN, Examiner.

my UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Pacent No. 3,335,004 Dated August 8, 1.967

Inventor(s) Kenneth L. Wrisley and Henry J. Fassbender It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 7, lines 6 and 7, which read Ethylenediamine tetraacetic acid, tetra sodium salt, sodium phosphate,

tribasic -----.-....30-] O0" should read ----Ethylenediamine tetraacetic acid, tetra sodium salt o.5 2.o

Sodium phosphate, tribasic -------30-l00 SIGNED AND SEALED MAY 5 1910 Attest:

WILLIAM 1:. seam, .m. Mtcating Officer Conmissioner at Patmtfl 

1. AN IMPROVED RAPID COLOR PHOTOGRAPHIC PROCESS WHICH COMPRISES DEVELOPING WITH A PRIMARY AROMATIC AMINE COLOR DEVELOPING BATH, AN EXPOSED COLOR PHOTOGRAPHIC MATERIAL COMPRISING DIFFERENTLY SENSITIZED GELATINOSILVER HALIDE EMULSIONS CONTAINING COLOR FORMERS CAPABLE OF REACTION WITH THE OXIDATION PRODUCT OF SAID DEVELOPER TO FORM A DYE, ARRESTING DEVELOPMENT BY PASSING THROUGH A STOP BATH CONTAINING AN INORGANIC BISULFITE, BLEACH STABILIZING WITH A BATH CONTAINING AN INORGANIC ALKALINE FERRICYANIDE, AN INORGANIC ALKALINE THIOCYANATE, AN INORGANIC ALKALINE BICROMATE, AND STABILIZING WITH A BATH CONTAINING AN INORGANIC ALKALINE THIOSULFATE, AN INORGANIC ALKALINE SULFITE, AND AN INORGANIC ALKALINE BISULFITE, SAID RAPID PROCESS CONSISTING OF TREATING SAID PHOTOGRAPHIC MATERIAL IN SAID DEVELOPER, SAID STOP BATH, SAID BLEACHSTABILIZING BATH AND SAID STABILIZING BATH IN THE SAID ORDER WITH NO WASHING, EACH OF THE SAID BATHS BEING DESIGNED TO PERFORM ITS INDICATED FUNCTION IN 30 SECONDS AT 100*F. 